u/FearTheCronin r/compsci • Recommends
On “are non-square circuits on the edge of wafers used for anything?”
link to this video
This may answer your question. The ingots are grown in a very specific way from a seed crystal and are cylindrical. The formation is due to crystalization rather than molten material solidifying (similar to rock candy). There are a limited number of shapes you can make while crystalizing the material.